Computer network systems often include network monitoring software systems to monitor the status of network nodes and links. The network monitoring software typically resides above the network driver level, maintaining information about the status of nodes on the network and providing information to the network drivers on the status of the communication links between nodes.
The specific problem to which the invention has application is implementing network monitoring for multiple interconnected networks in which two nodes on different networks are required to communicate through a third node that operates as a bridge node between the networks. Such multiple network systems may be of the same type, such as two ethernets, or dissimilar, such as an ethernet and a token ring.
The current approach to network monitoring systems relies on a master monitor system resident in a node designated as the master. The master monitor implements all of the processing associated with determining the status of all nodes on the network, and distributing that status to the other nodes.
A master monitor system cannot be used unless the master monitor resident in the master node can establish a communication link to every other node on the system. In particular, the master monitor system is not compatible with a multiple network architecture in which a node on one network and a node on a second network can both communicate with a bridge node, but cannot communicate directly with each other.
In addition, a master oriented system necessarily requires that substantially all monitor processing be performed by the master monitor node. Thus, even if a master oriented system could be configured for multiple-network architectures, if the bridge node fails, the monitor system would be lost for those nodes on the side of the bridge node opposite the master monitor node.
Moreover, current master monitor systems do not provide any information about the condition of links that, while on-line and useable, nevertheless offer significantly degraded performance. In particular, identifying whether a performance degradation is caused by a source or destination node is problematic, even with statistical data on link attempts and errors that is available from many communications drivers.
Accordingly, a specific need exists for a network monitor architecture compatible with multiple networks in which two nodes on different networks are still able to communicate by routing through a bridge node. Ideally, such a network monitoring system would include an improved procedure for positively determining those nodes with intermittent communications links.